1. Field of the Invention
The present invention relates to a signal recording/reproduction method and apparatus that optimizes the laser beam intensity, magnetic field intensity, phase difference between a laser beam and a magnetic field, and an equalizer coefficient according to a reproduced signal in recording and/or reproducing a signal to and/or from a magneto recording medium to record and/or reproduce a signal to and/from a magneto-optical recording medium according to the optimized results.
2. Description of the Background Art
Attention is focused on a magneto-optical recording medium as a rewritable and reliable recording medium of large storage capacity. Magneto-optical recording media are now being adapted to practical use as a computer memory or the like. Standardization of a magneto-optical recording medium having a recording capacity of 6.0 Gbytes is in progress for practical applications. Reproduction of a signal from such a magneto-optical recording medium of high density is carried out by the MSR (magnetically induced super resolution) method in which a magnetic domain of a recording layer in a magneto-optical recording medium is transferred to a region of a reproduction layer exceeding a predetermined temperature by projecting a laser beam, and detecting the transferred magnetic domain.
In recording a signal on a magneto-optical recording medium using a pulsed laser beam (referred to as xe2x80x9cpulse beamxe2x80x9d hereinafter) and a magnetic domain modulated by a recording signal, the phase difference between the pulse beam and the magnetic field must be optimized. There was a problem that a signal cannot be recorded properly when a magnetic field is applied at a timing where the magnetic film of the magneto-optical recording medium is not increased to the temperature that can alter the direction of magnetization by an external magnetic field.
From the standpoint of recording a signal at high density to a magneto-optical recording medium, there was a problem that a small magnetic domain cannot be formed if the intensity of the pulse beam projected on the magneto-optical recording medium is too strong since a region wider than the desired region will attain a temperature exceeding the predetermined temperature.
In the case where the intensity of the pulse beam projected on the magneto-optical recording medium is too strong during signal recording in the land/groove scheme, an adjacent land or groove will also attain a temperature higher than the predetermined temperature so that a signal already recorded will be erased.
If the intensity of the magnetic field applied on the magneto-optical recording medium during signal recording is too weak, it will be difficult to form a magnetic domain having the desired direction of magnetization in the magnetic layer. There was problem that a signal cannot be recorded properly.
Various problems are also encountered in reproducing a signal from a magneto-optical recording medium. If the intensity of the laser beam projected onto the magneto-optical recording medium is too weak, the intensity of the reproduced signal is reduced to degrade the S/N. If the intensity of the laser beam is too strong, a signal will be reproduced also from an adjacent land or groove to cause crosstalk.
There is also the case where waveform interference occurs in the magneto-optical signal reproduced by a laser beam. Since the amplitude of a magneto-optical signal with waveform interference is small, it is necessary to remove the waveform interference.
In view of the foregoing, an object of the present invention is to provide a signal recording/reproduction method and apparatus to record and/or reproduce a signal properly to and/or from a magneto-optical recording medium by optimizing the phase difference between the pulse beam and the magnetic field, the intensity of the pulse beam, and the intensity of the magnetic field in recording a signal, and also the intensity of the laser beam and the equalizer coefficient to remove waveform interference in reproducing a signal, and recording and/or reproducing a signal to and/or from a magneto-optical recording medium according to the optimized results.
According to an aspect of the present invention, a recording/reproduction apparatus recording and/or reproducing a signal to and/or from a magneto-optical recording medium includes an optical head projecting laser beam onto a magneto-optical recording medium and detecting reflected light thereof, a laser drive circuit driving a semiconductor laser in the optical head, a magnetic head applying a magnetic field to the magneto-optical recording medium, a magnetic head drive circuit driving the magnetic head, and a control circuit.
The control circuit generates a first driving signal for the magnetic head to generate a magnetic field of a predetermined intensity modulated by a recording signal. The generated first driving signal is provided to the magnetic head drive circuit.
The control circuit generates a second driving signal for the optical head to emit a pulse beam of a predetermined intensity with the phase difference from the first driving signal altered. The generated second driving signal is provided to the laser drive circuit.
The optimum phase difference between the first and second driving signals is determined according to a magneto-optical signal reproduced by the optical head corresponding to a signal recorded on the magneto-optical recording medium with the phase difference between the first and second driving signals altered according to the first and second driving signals.
According to the recording/reproduction apparatus of the present aspect, a first driving signal to apply a magnetic field is generated, in addition to a second driving signal to generate a pulse beam with the phase difference from the first driving signal altered. A predetermined signal is recorded on the magneto-optical recording medium according to the first and second driving signals. The optimum phase difference between the first and second driving signals is determined according to a magneto-optical signal which is a reproduced version of that recorded signal.
According to the invention of the present aspect, the correct phase difference can be determined to allow proper signal recording since a signal is actually recorded on a magneto-optical recording medium and the phase difference is determined according to a reproduced signal thereof.
According to another aspect of the present invention, a recording/reproduction apparatus recording and/or reproducing a signal to and/or from a magneto-optical recording medium includes an optical head projecting laser beam onto a magneto-optical recording medium and detecting reflected light thereof, a laser drive circuit driving a semiconductor laser in the optical head, a magnetic head applying a magnetic field to the magneto-optical recording medium, a magnetic head drive circuit driving the magnetic head, and a control circuit.
The control circuit generates a first driving signal for the magnetic head to generate a magnetic field of a predetermined intensity modulated by a recording signal. The first driving signal is provided to the magnetic head drive circuit.
The control circuit generates a second driving signal for the optical head to emit a pulse beam of a predetermined intensity. The second driving signal has an optimum phase difference from the first driving signal. The second driving signal is provided to the laser drive circuit.
After a signal is recorded on the magneto-optical recording medium by the first and second driving signals, the control circuit generates a third driving signal that alters the intensity of the laser beam to reproduce the recorded signal. The generated third driving signal is provided to the laser drive circuit.
The control circuit determines a provisional optimum laser beam intensity for the optical head to reproduce a signal according to a magneto-optical signal reproduced from the magneto-optical recording medium according to the third driving signal, and generates a fourth driving signal to set the intensity of the laser beam to the determined provisional optimum laser beam intensity. The generated fourth driving signal is provided to the laser drive circuit.
A provisional optimum equalizer coefficient to remove waveform interference is determined according to a magneto-optical signal removed of waveform interference corresponding to a magneto-optical signal reproduced from the magneto-optical recording medium by the optical head according to the fourth driving signal with the equalizer coefficient of the equalizer altered. The equalizer coefficient of the equalizer is set to the provisional optimum equalizer coefficient.
In the recording/reproduction apparatus of the present aspect, the phase difference is optimized between the first driving signal generating a magnetic field to be applied to the magneto-optical recording medium in signal recording and a second driving signal generating a pulse beam to be projected on the magneto-optical recording medium, followed by determination of a provisional optimum laser beam intensity in reproducing a recording signal. The equalizer coefficient of the equalizer which is one of the reproduced signal processing system is optimized provisionally according to the optimum phase difference and the provisional optimum laser beam intensity.
According to the invention of the present aspect, optimization can be effected also for the signal reproduction system in addition to the optical system that directly detects a signal from a magneto-optical recording medium.
According to a further aspect of the present invention, a recording/reproduction apparatus recording and/or reproducing a signal to and/or from a magneto-optical recording medium includes an optical head projecting laser beam onto a magneto-optical recording medium and detecting reflected light thereof, a laser drive circuit driving a semiconductor laser in the optical head, a magnetic head applying a magnetic field to the magneto-optical recording medium, a magnetic head drive circuit driving the magnetic head, and a control circuit.
The control circuit generates a first driving signal for the magnetic head to generate a magnetic field of a predetermined intensity modulated by a recording signal. The first driving signal is provided to the magnetic head drive circuit.
The control circuit generates a second driving signal for the optical head to emit a pulse beam of a predetermined intensity. The second driving signal has an optimum phase difference from the first driving signal. The second driving signal is provided to the laser drive circuit.
After a signal is recorded on the magneto-optical recording medium by the first and second driving signals, the control circuit generates a fourth driving signal to set a provisional optimum laser beam intensity to reproduce that recorded signal. The fourth driving signal is provided to the laser drive circuit.
A provisional optimum equalizer coefficient in removing waveform interference from a magneto-optical signal reproduced from the magneto-optical recording medium by the optical head using a laser beam according to the fourth driving signal is determined. The equalizer coefficient of the equalizer is set to the determined provisional optimum equalizer coefficient.
After the optimum phase difference between the first and second driving signals, the provisional optimum laser beam intensity, and the provisional optimum equalizer coefficient are determined, the control circuit generates a fifth driving signal for the magnetic head to generate a magnetic field modulated by a recording signal and having the maximum magnetic field intensity. The fifth driving signal is provided to the magnetic head drive circuit.
The control circuit generates a sixth driving signal for the optical head to emit a pulse beam whose intensity is altered. The sixth driving signal has an optimum phase difference from the fifth driving signal. The sixth driving signal is provided to the laser drive circuit.
The servo circuit is controlled so that a signal is recorded in the order of a land of a magneto-optical recording medium, a first groove adjacent to the land, and a second groove adjacent to the land, or in the order of a groove of a magneto-optical recording medium, a first land adjacent to the groove, and a second land adjacent to the groove according to the fifth and sixth driving signals.
After a signal is recorded in the order of a land, a first groove, and a second groove, or in the order of a groove, a first land, and a second land according to the fifth and sixth driving signals, an optimum pulse beam intensity is determined to record a signal according to a magneto-optical signal reproduced by the optical head corresponding to the signal recorded on the land or groove by the optimum laser beam.
In the recording/reproduction apparatus of the present aspect, after optimizing the phase difference between the first driving signal generating a magnetic field to be applied to a magneto-optical recording medium in signal recording and the second driving signal generating a pulse beam to be projected on the magneto-optical recording medium, determining a provisional optimum laser beam intensity for reproduction of a recording signal, and optimizing provisionally the equalizer coefficient of the equalizer which is one of the reproduced signal processing system according to the optimum phase difference and the provisional optimum laser beam intensity, the intensity of the pulse beam for recording a signal onto a magneto-optical recording medium is optimized based on the optimum phase difference between the magnetic field and pulse beam in recording a signal, the provisional optimum laser beam intensity for signal reproduction, and the provisional optimum equalizer coefficient.
According to the invention of the present aspect, the proper pulse beam intensity can be determined since the intensity of the pulse beam is optimized also including the signal processing system in addition to the optical head and the magnetic head. Also, the optimum pulse beam intensity can be determined in the normal usage status since the signal recorded at the land (or groove) is reproduced after recording the signal in the order of the land (or groove), the first groove adjacent to that land (or groove), and the second groove (or first land, second land) in recording a signal with the intensity of the pulse beam altered.
According to still another aspect of the present invention, a recording/reproduction apparatus recording and/or reproducing a signal to and/or from a magneto-optical recording medium includes an optical head projecting laser beam onto a magneto-optical recording medium and detecting reflected light thereof, a laser drive circuit driving a semiconductor laser in the optical head, a magnetic head applying a magnetic field to the magneto-optical recording medium, a magnetic head drive circuit driving the magnetic head, and a control circuit.
The control circuit generates a first driving signal for the magnetic head to generate a magnetic field of a predetermined intensity modulated by a recording signal. The first driving signal is provided to the magnetic head drive circuit.
The control circuit generates a second driving signal for the optical head to emit a pulse beam of a predetermined intensity. The second driving signal has an optimum phase difference from the first driving signal. The second driving signal is provided to the laser drive circuit.
After a signal is recorded on the magneto-optical recording medium by the first and second driving signals, the control circuit generates a fourth driving signal to set a provisional optimum laser beam intensity for reproduction of the recorded signal. The fourth driving signal is provided to the laser drive circuit.
The provisional optimum equalizer coefficient in removing waveform interference from a magneto-optical signal reproduced from the magneto-optical recording medium using a laser beam according to the fourth driving signal by the optical head is determined. The equalizer coefficient of the equalizer is set to that determined provisional optimum equalizer coefficient.
After the optimum phase difference between the first and second driving signals, the provisional optimum laser beam intensity, and the provisional optimum equalizer coefficient are determined, the control circuit generates a fifth driving signal for the optical head to generate a magnetic field modulated by the recording signal and having the greatest magnetic field intensity. The fifth driving signal is provided to the magnetic head drive circuit.
The control circuit generates a seventh driving signal for the optical head to emit a pulse beam having the optimum intensity to record a signal on a magneto-optical recording medium and determined using the optimum phase difference between the first and second driving signals, the provisional optimum laser beam intensity, and the provisional optimum equalizer coefficient. The seventh driving signal has an optimum phase difference from the fifth driving signal. The seventh driving signal is provided to the laser drive circuit.
The servo circuit is controlled so that a signal is recorded on a magneto-optical recording medium in the order of a land, a first groove adjacent to that land, and a second groove adjacent to the land, or in the order of a groove, a first land adjacent to that groove, and a second land adjacent to that groove, according to the fifth and seventh driving signals.
After a signal is recorded on a land, a first groove, and a second groove, or at a groove, a first land, and a second land according to the fifth and seventh driving signals, the control circuit generates an eighth driving signal for the optical head to reproduce a signal recorded at the land or groove with the intensity of the laser beam altered. The eighth driving signal is provided to the laser drive circuit.
The optimum laser beam intensity is determined according to the magneto-optical recording signal reproduced from the land or groove based on the eighth driving signal by the optical head.
In the recording/reproduction apparatus of the present aspect, after optimizing the phase difference between the first driving signal generating a magnetic field to be applied to a magneto-optical recording medium in signal recording and the second driving signal generating a pulse beam to be projected on the magneto-optical recording medium, the provisional optimum laser beam intensity in reproducing a recording signal, a provisional optimum equalizer coefficient, and the laser beam intensity in recording a signal onto a magneto-optical recording medium, the laser beam intensity in reproducing a signal is optimized using conditions already optimized or provisionally optimized.
According to the invention of the present aspect, an optimum laser beam intensity for reproduction can be determined.
According to a still further aspect of the present invention, a recording/reproduction apparatus recording and/or reproducing a signal to and/or from a magneto-optical recording medium includes an optical head projecting laser beam onto a magneto-optical recording medium and detecting reflected light thereof, a laser drive circuit driving a semiconductor laser in the optical head, a magnetic head applying a magnetic field to the magneto-optical recording medium, a magnetic head drive circuit driving the magnetic head, and a control circuit.
The control circuit generates a first driving signal for the magnetic head to generate a magnetic field of a predetermined intensity modulated by a recording signal. The first driving signal is provided to the magnetic head drive circuit.
The control circuit generates a second driving signal for the optical head to emit a pulse beam of a predetermined intensity. The second driving signal has an optimum phase difference from the first driving signal. The second driving signal is provided to the laser drive circuit.
After a signal is recorded on the magneto-optical recording medium by the first and second driving signals, the control circuit generates a fourth driving signal to set a provisional optimum laser beam intensity for reproduction of the recorded signal. The fourth driving signal is provided to the laser drive circuit.
The provisional optimum equalizer coefficient in removing waveform interference from a magneto-optical signal reproduced from the magneto-optical recording medium using a laser beam according to the fourth driving signal by the optical head is determined. The equalizer coefficient of the equalizer is set to that determined provisional optimum equalizer coefficient.
After the optimum phase difference between the first and second driving signals, the provisional optimum laser beam intensity, and the provisional optimum equalizer coefficient are determined, the control circuit generates a fifth driving signal for the magnetic head to generate a magnetic field modulated by the recording signal and having the greatest magnetic field intensity. The fifth driving signal is provided to the magnetic head drive circuit.
The control circuit generates a seventh driving signal for the optical head to emit a pulse beam having the optimum intensity to record a signal on a magneto-optical recording medium, determined using the optimum phase difference between the first and second driving signals, the previous optimum laser beam intensity, and the provisional optimum equalizer coefficient. The seventh driving signal has an optimum phase difference from the fifth driving signal. The seventh driving signal is provided to the laser drive circuit.
The servo circuit is controlled so that a signal is recorded on a magneto-optical recording medium in the order of a land, a first groove adjacent to that land, and a second groove adjacent to the land, or in the order of a groove, a first land adjacent to that groove, and a second land adjacent to that groove, according to the fifth and seventh driving signals.
After a signal is recorded at a land, a first groove, and a second groove, or at a groove, a first land, and a second land according to the fifth and seventh driving signals, the control circuit generates a ninth driving signal for the optical head to emit a laser beam of the optimum intensity to reproduce a signal recorded at the land or groove. The ninth driving signal is provided to the laser drive circuit. The optimum equalizer coefficient to remove waveform interference is determined according to a magneto-optical signal removed of waveform interference corresponding to a magneto-optical signal reproduced from the signal recorded at a land or groove according to the ninth driving signal by the optical head with the equalizer coefficient of the equalizer altered. The equalizer coefficient of the equalizer is set as the optimum equalizer coefficient.
In the recording/reproduction apparatus of the present aspect, after optimizing the phase difference between the first driving signal generating a magnetic field to be applied to the magneto-optical recording medium in signal recording and the second driving signal generating a pulse beam to be projected onto the magneto-optical recording medium, a provisional equalizer coefficient, intensity of the pulse beam in recording a signal onto a magneto-optical recording medium, and the laser beam intensity in reproducing a signal, the equalizer coefficient of the equalizer which is one of the signal processing system is optimized using conditions that are already or provisionally optimized.
According to the invention of the present aspect, the proper equalizer coefficient can be determined.
According to yet a further aspect of the present invention, a recording/reproduction apparatus recording and/or reproducing a signal to and/or from a magneto-optical recording medium includes an optical head projecting laser beam onto a magneto-optical recording medium and detecting reflected light thereof, a laser drive circuit driving a semiconductor laser in the optical head, a magnetic head applying a magnetic field to the magneto-optical recording medium, a magnetic head drive circuit driving the magnetic head, and a control circuit.
The control circuit generates a first driving signal for the magnetic head to generate a magnetic field of a predetermined intensity modulated by a recording signal. The first driving signal is provided to the magnetic head drive circuit.
The control circuit generates a second driving signal for the optical head to emit a pulse beam of a predetermined intensity. The second driving signal has an optimum phase difference from the first driving signal. The second driving signal is provided to the laser drive circuit.
After a signal is recorded on the magneto-optical recording medium by the first and second driving signals, the control circuit generates a fourth driving signal to set a provisional optimum laser beam intensity for reproduction of the recorded signal. The fourth driving signal is provided to the laser drive circuit.
The provisional optimum equalizer coefficient in removing waveform interference from a magneto-optical signal reproduced from the magneto-optical recording medium using a laser beam according to the fourth driving signal by the optical head is determined. The equalizer coefficient of the equalizer is set to that determined provisional optimum equalizer coefficient.
After the optimum phase difference between the first and second driving signals, the provisional optimum laser beam intensity, and the provisional optimum equalizer coefficient are determined, the control circuit generates a fifth driving signal for the magnetic head to generate a magnetic field modulated by the recording signal and having the greatest magnetic field intensity. The fifth driving signal is provided to the magnetic head drive circuit.
The control circuit generates a seventh driving signal for the optical head to emit a pulse beam having the optimum intensity to record a signal on a magneto-optical recording medium, determined using the optimum phase difference between the first and second driving signals, the provisional optimum laser beam intensity, and the provisional optimum equalizer coefficient. The seventh driving signal has an optimum phase difference from the fifth driving signal. The seventh driving signal is provided to the laser drive circuit.
The servo circuit is controlled so that a signal is recorded on a magneto-optical recording medium in the order of a land, a first groove adjacent to that land, and a second groove adjacent to the land, or in the order of a groove, a first land adjacent to that groove, and a second land adjacent to that groove, according to the fifth and seventh driving signals.
After a signal is recorded at a land, a first groove, and a second groove, or at a groove, a first land, and a second land according to the fifth and seventh driving signals, the control circuit generates a ninth driving signal for the optical head to emit a laser beam of the optimum intensity to reproduce a signal recorded at the land. The ninth driving signal is provided to the laser drive circuit. The equalizer coefficient of the equalizer is set to the optimum equalizer coefficient determined from the magneto-optical signal which is a reproduced version of the signal recorded at the land or groove by the optical head according to the ninth driving signal.
The control circuit generates a tenth driving signal for the magnetic head to generate a magnetic field modulated by the recording signal to be altered in intensity. The tenth driving signal has a phase identical to that of the fifth driving signal. The tenth driving signal is provided to the magnetic head drive circuit.
The optimum magnetic field intensity to record a signal is determined from the magneto-optical signal reproduced by the optical head according to the ninth driving signal corresponding to the signal recorded to the magneto-optical recording medium according to the seventh and tenth driving signals.
In the recording/reproduction apparatus of the present aspect, after optimizing the phase difference between the first driving signal generating a magnetic field to be applied to a magneto-optical recording medium and the second driving signal generating a pulse beam to be projected onto the magneto-optical recording medium in signal recording, the optimum equalizer coefficient in reproducing a recording signal, the pulse beam intensity in recording a signal onto a magneto-optical recording medium, and the laser beam intensity in reproducing a signal, the magnetic field intensity in recording a signal is optimized using the conditions already optimized.
According to the invention of the present aspect, conditions sensitive to the recording property and reproduction property of a signal are previously optimized, and other conditions are optimized based on the optimized sensitive conditions. Therefore, the conditions can be optimized efficiently and properly.
According to yet another aspect of the present invention, a recording/reproduction apparatus recording and/or reproducing a signal to and/or from a magneto-optical recording medium includes an optical head projecting laser beam onto a magneto-optical recording medium and detecting reflected light thereof, a laser drive circuit driving a semiconductor laser in the optical head, a magnetic head applying a magnetic field to the magneto-optical recording medium, a magnetic head drive circuit driving the magnetic head, and a control circuit.
The control circuit generates a first driving signal for the magnetic head to generate a magnetic field of a predetermined intensity modulated by a recording signal. The first driving signal is provided to the magnetic head drive circuit.
The control circuit generates a second driving signal for the optical head to emit a pulse beam of a predetermined intensity. The second driving signal has an optimum phase difference from the first driving signal. The second driving signal is provided to the laser drive circuit.
After a signal is recorded on the magneto-optical recording medium by the first and second driving signals, the control circuit generates a fourth driving signal to set a provisional optimum laser beam intensity for reproduction of the recorded signal. The fourth driving signal is provided to the laser drive circuit.
The provisional optimum equalizer coefficient in removing waveform interference from a magneto-optical signal reproduced from the magneto-optical recording medium using a laser beam according to the fourth driving signal by the optical head is determined. The equalizer coefficient of the equalizer is set to that determined provisional optimum equalizer coefficient.
After the optimum phase difference between the first and second driving signals, the provisional optimum laser beam intensity, and the provisional optimum equalizer coefficient are determined, the control circuit generates a fifth driving signal for the magnetic head to generate a magnetic field modulated by the recording signal and having the greatest magnetic field intensity. The fifth driving signal is provided to the magnetic head drive circuit.
The control circuit generates a seventh driving signal for the optical head to emit a pulse beam having the optimum intensity to record a signal on a magneto-optical recording medium, determined using the optimum phase difference between the first and second driving signals, the provisional optimum laser beam intensity, and the provisional optimum equalizer coefficient. The seventh driving signal has an optimum phase difference from the fifth driving signal. The seventh driving signal is provided to the laser drive circuit.
The servo circuit is controlled so that a signal is recorded on a magneto-optical recording medium in the order of a land, a first groove adjacent to that land, and a second groove adjacent to the land, or in the order of a groove, a first land adjacent to that groove, and a second land adjacent to that groove, according to the fifth and seventh driving signals.
After a signal is recorded on a land, a first groove, and a second groove, or at a groove, a first land, and a second land according to the fifth and seventh driving signals, the control circuit generates a ninth driving signal for the optical head to emit a laser beam of the optimum intensity to reproduce a signal recorded at the land. The ninth driving signal is provided to the laser drive circuit. The equalizer coefficient of the equalizer is set to the optimum equalizer coefficient determined from the magneto-optical signal which is a reproduced version of the signal recorded at the land or groove by the optical head according to the ninth driving signal.
The control circuit generates a tenth driving signal for the magnetic head to generate a magnetic field modulated by the recording signal to have intensity altered. The tenth driving signal has a phase identical to that of the fifth driving signal. The tenth driving signal is provided to the magnetic head drive circuit.
The optimum magnetic field intensity to record a signal is determined from the magneto-optical signal reproduced by the optical head according to the ninth driving signal corresponding to the signal recorded to the magneto-optical recording medium according to the seventh and tenth driving signals. The control circuit generates an eleventh driving signal having that determined intensity. The eleventh driving signal has a phase identical to that of the fifth driving signal.
A signal is recorded and/or reproduced to and/or from a magneto-optical recording medium according to the optimum phase difference, optimum equalizer coefficient, the seventh driving signal, the ninth driving signal and the eleventh driving signal.
In the signal/reproduction apparatus of the present aspect, after optimizing the phase difference between the first driving signal generating a magnetic field to be applied onto a magneto-optical recording medium in signal recording and the second driving signal generating a pulse beam projected onto a magneto-optical recording medium, the equalizer coefficient, the pulse beam intensity in recording a signal onto the magneto-optical recording medium, the laser beam intensity in reproducing a signal, and the recording magnetic field intensity, a signal is recorded and/or reproduced to and/or from a magneto-optical recording medium according to the optimized conditions.
According to the invention of the present aspect, conditions sensitive to the recording and reproduction properties of a signal are previously optimized, and other conditions optimized according to the optimized sensitive conditions. Therefore, the conditions can be optimized efficiently and properly. Correct signal recording and reproduction are allowed since a signal can be recorded or reproduced with respect to the magneto-optical recording medium according to the optimized result.
According to yet a still further aspect of the present invention, a recording/reproduction apparatus recording and/or reproducing a signal to and/or from a magneto-optical recording medium includes an optical head projecting laser beam onto a magneto-optical recording medium and detecting reflected light thereof, a laser drive circuit driving a semiconductor laser in the optical head, a magnetic head applying a magnetic field to the magneto-optical recording medium, a magnetic head drive circuit driving the magnetic head, and a control circuit.
The control circuit generates a first driving signal for the magnetic head to generate a magnetic field of a predetermined intensity modulated by a recording signal. The first driving signal is provided to the magnetic head drive circuit.
The control circuit generates a second driving signal for the optical head to emit a pulse beam of a predetermined intensity. The second driving signal has an optimum phase difference from the first driving signal. The second driving signal is provided to the laser drive circuit.
After a signal is recorded on the magneto-optical recording medium by the first and second driving signals, the control circuit generates a fourth driving signal to set a provisional optimum laser beam intensity for reproduction of the recorded signal. The fourth driving signal is provided to the laser drive circuit.
The provisional optimum equalizer coefficient in removing waveform interference from a magneto-optical signal reproduced from the magneto-optical recording medium using a laser beam according to the fourth driving signal by the optical head is determined. The equalizer coefficient of the equalizer is set to that determined provisional optimum equalizer coefficient.
After the optimum phase difference between the first and second driving signals, the provisional optimum laser beam intensity, and the provisional optimum equalizer coefficient are determined, the control circuit generates a fifth driving signal for the magnetic head to generate a magnetic field modulated by the recording signal and having the greatest magnetic field intensity. The fifth driving signal is provided to the magnetic head drive circuit.
The control circuit generates a seventh driving signal for the optical head to emit a pulse beam having the optimum intensity to record a signal on a magneto-optical recording medium, determined using the optimum phase difference between the first and second driving signals, the provisional optimum laser beam intensity, and the provisional optimum equalizer coefficient. The seventh driving signal has an optimum phase difference from the fifth driving signal. The seventh driving signal is provided to the laser drive circuit.
The servo circuit is controlled so that a signal is recorded on a magneto-optical recording medium in the order of a land, a first groove adjacent to that land, and a second groove adjacent to the land, or in the order of a groove, a first land adjacent to that groove, and a second land adjacent to that groove, according to the fifth and seventh driving signals.
After a signal is recorded on a land, a first groove, and a second groove, or at a groove, a first land, and a second land according to the fifth and seventh driving signals, the control circuit generates a ninth driving signal for the optical head to emit a laser beam of the optimum intensity to reproduce a signal recorded at the land. The ninth driving signal is provided to the laser drive circuit. The equalizer coefficient of the equalizer is set to the optimum equalizer coefficient determined from the magneto-optical signal which is a reproduced version of the signal recorded at the land or groove by the optical head according to the ninth driving signal.
The control circuit generates a tenth driving signal for the magnetic head to generate a magnetic field modulated by the recording signal to have the intensity altered. The tenth driving signal has a phase identical to that of the fifth driving signal. The tenth driving signal is provided to the magnetic head drive circuit.
The optimum magnetic field intensity to record a signal is determined from the magneto-optical signal reproduced by the optical head according to the ninth driving signal corresponding to the signal recorded to the magneto-optical recording medium according to the seventh and tenth driving signals. The control circuit generates an eleventh driving signal having that determined intensity. The eleventh driving signal has a phase identical to that of the fifth driving signal.
After the optimum phase difference and optimum equalize coefficient are determined, and after the seventh driving signal for a land or groove, the ninth driving signal and the eleventh driving signal are generated, a provisional optimum laser beam intensity for the groove or land is determined. A pulse beam having the optimum intensity and a laser beam having the optimum intensity are determined based on the determined provisional optimum laser beam intensity. The control circuit provides a twelfth driving signal to generate a pulse beam having the optimum intensity, and a thirteenth driving signal to generate a laser beam having the optimum intensity.
A signal is recording and/or reproduced to/from a magneto-optical recording medium according to the optimum phase difference, optimum equalizer coefficient, seventh driving signal, ninth driving signal, eleventh driving signal, twelfth driving signal, and thirteenth driving signal.
According to the recording/reproduction apparatus of the present aspect, the phase difference between the first driving signal generating a magnetic field to be applied to the magneto-optical recording medium in signal recording and the second driving signal generating a pulse beam to be projected to a magneto-optical recording medium, the equalizer coefficient, the pulse beam intensity in recording a signal to a magneto-optical recording medium, the laser beam intensity in reproducing a signal, and the recording magnetic field intensity are set separately for both a land and groove. When the optimized conditions differ between the land and groove, signal recording and/or reproduction with respect to the magneto-optical recording medium is carried out using respective optimum conditions.
According to the invention of the present aspect, a signal can be recorded and/or reproduced more correctly since conditions can be optimized for the land and groove respectively.
According to an additional aspect of the present invention, a recording/reproduction apparatus recording and/or reproducing a signal to and/or from a magneto-optical recording medium includes an optical head projecting laser beam onto a magneto-optical recording medium and detecting reflected light thereof, a laser drive circuit driving a semiconductor laser in the optical head, a magnetic head applying a magnetic field to the magneto-optical recording medium, a magnetic head drive circuit driving the magnetic head, and a control circuit.
The control circuit generates a first driving signal for the magnetic head to generate a magnetic field of a predetermined intensity modulated by a recording signal. The first driving signal is provided to the magnetic head drive circuit.
The control circuit generates a second driving signal for the optical head to emit a pulse beam of a predetermined intensity. The second driving signal has an optimum phase difference from the first driving signal. The second driving signal is provided to the laser drive circuit.
After a signal is recorded on the magneto-optical recording medium by the first and second driving signals, the control circuit generates a fourth driving signal to set a provisional optimum laser beam intensity for reproduction of the recorded signal. The fourth driving signal is provided to the laser drive circuit.
The provisional optimum equalizer coefficient in removing waveform interference from a magneto-optical signal reproduced from the magneto-optical recording medium using a laser beam according to the fourth driving signal by the optical head is determined. The equalizer coefficient of the equalizer is set to that determined provisional optimum equalizer coefficient.
After the optimum phase difference between the first and second driving signals, the provisional optimum laser beam intensity, and the provisional optimum equalizer coefficient are determined, the control circuit generates a fifth driving signal for the magnetic head to generate a magnetic field modulated by the recording signal and having the greatest magnetic field intensity. The fifth driving signal is provided to the magnetic head drive circuit.
The control circuit generates a seventh driving signal for the optical head to emit a pulse beam having the optimum intensity to record a signal on a magneto-optical recording medium, determined using the optimum phase difference between the first and second driving signals, the provisional optimum laser beam intensity, and the provisional optimum equalizer coefficient. The seventh driving signal has an optimum phase difference from the fifth driving signal. The seventh driving signal is provided to the laser drive circuit.
The servo circuit is controlled so that a signal is recorded on a magneto-optical recording medium in the order of a land, a first groove adjacent to that land, and a second groove adjacent to the land, or in the order of a groove, a first land adjacent to that groove, and a second land adjacent to that groove, according to the fifth and seventh driving signals.
After a signal is recorded on a land, a first groove, and a second groove, or at a groove, a first land, and a second land according to the fifth and seventh driving signals, the control circuit generates a ninth driving signal for the optical head to emit a laser beam of the optimum intensity to reproduce a signal recorded at the land. The ninth driving signal is provided to the laser drive circuit. The equalizer coefficient of the equalizer is set to the optimum equalizer coefficient determined from the magneto-optical signal which is a reproduced version of the signal recorded at the land or groove by the optical head according to the ninth driving signal.
The control circuit generates a tenth driving signal for the magnetic head to generate a magnetic field modulated by the recording signal whose intensity is altered. The tenth driving signal has a phase identical to that of the fifth driving signal. The tenth driving signal is provided to the magnetic head drive circuit.
The optimum magnetic field intensity to record a signal is determined from the magneto-optical signal reproduced by the optical head according to the ninth driving signal corresponding to the signal recorded to the magneto-optical recording medium according to the seventh and tenth driving signals. The control circuit generates an eleventh driving signal having that determined intensity. The eleventh driving signal has a phase identical to that of the fifth driving signal.
After the optimum phase difference and optimum equalize coefficient are determined, and after the seventh driving signal for a land or groove, the ninth driving signal and the eleventh driving signal are generated, a provisional optimum laser beam intensity for the groove or land is determined. A pulse beam having the optimum intensity and a laser beam having the optimum intensity are determined based on the determined provisional optimum laser beam intensity. The control circuit provides a twelfth driving signal to generate a pulse beam having the optimum intensity, and a thirteenth driving signal to generate a laser beam having the optimum intensity.
According to the optimum phase difference, the optimum equalizer coefficient, the seventh driving signal, a fourteenth driving signal having as an amplitude the average of the amplitude of the ninth and twelfth driving signals and a phase identical to those of the ninth and twelfth driving signals, and a fifteenth driving signal having as the amplitude the average of the amplitude of the eleventh and thirteenth driving signals, and a phase identical to that of the eleventh and thirteenth driving signals, a signal is recording and/or reproduced to/from a magneto-optical recording medium.
In the recording/reproduction apparatus of the present aspect, the phase difference between the first driving signal generating a magnetic field to be applied to a magneto-optical recording medium in signal recording and the second driving signal generating a pulse beam to be projected onto a magneto-optical recording medium, the equalizer coefficient, the pulse beam intensity in recording a signal onto a magneto-optical recording medium, a laser beam intensity in reproducing a signal and the recording magnetic field intensity are optimized respectively for the land and groove. When the optimized conditions differ between the land and groove, a signal is recorded and/or reproduced to/from a magneto-optical recording medium using the average of respective optimum conditions.
According to the invention of the present aspect, the optimum conditions can be determined for both the land and groove.
According to another aspect of the present invention, a recording/reproduction method of recording and/or reproducing a signal to and/or from a magneto-optical recording medium includes: a first step of determining an optimum phase difference between a pulse beam and a magnetic field to record a signal onto a magneto-optical recording medium; a second step of recording a signal onto a magneto-optical recording medium using the optimum phase difference determined at the first step, reproducing that recorded signal with a laser beam whose intensity is altered, and determining a provisional optimum laser beam intensity according to the reproduced magneto-optical signal; a third step of recording a signal onto a magneto-optical recording medium using the optimum phase difference determined by the first step, and determining a provisional optimum equalizer coefficient of an equalizer that removes waveform interference of a magneto-optical signal corresponding to the recorded signal reproduced using the provisional optimum laser beam intensity determined at the second step; a fourth step of recording a signal at a land of a magneto-optical recording medium, a first groove adjacent to the land, and a second groove adjacent to the land using the optimum phase difference determined at the first step with the intensity of the pulse beam altered, and determining an optimum pulse beam intensity to record a signal according to a magneto-optical signal corresponding to the signal recorded on the land reproduced using the provisional optimum laser beam intensity determined at the second step, and the provisional optimum equalizer coefficient determined at the third step; a fifth step of recording a signal in the order of a land, a first groove, and a second groove using the pulse beam having the optimum intensity determined at the fourth step and the magnetic field having the optimum phase difference from the pulse beam determined at the first step and the maximum intensity modulated by a recording signal, reproducing the signal recorded at the land with the intensity of the laser beam altered, and determining an optimum laser beam intensity to reproduce a signal according to a magneto-optical signal removed of waveform interference corresponding to the reproduced magneto-optical signal using the provisional optimum equalizer coefficient determined at the third step; a sixth step of recording a signal in the order of a land, a first groove and a second groove using a pulse beam having the optimum intensity determined at the fourth step and a magnetic field having the optimum phase difference from the pulse beam determined at the first step and the maximum intensity modulated by a recording signal, reproducing the recorded signal on the land using the laser beam of the optimum intensity determined at the fifth step, and determining the optimum equalizer coefficient according to a magneto-optical signal removed of waveform interference corresponding to the reproduced magneto-optical signal with the equalizer coefficient altered; and a seventh step of recording a signal in the order of a land, a first groove, and a second groove using a pulse beam having the optimum intensity determined at the fourth step and a magnetic field having the optimum phase difference from the pulse beam determined at the first step and an intensity modulated by a recording signal to be altered, reproducing the signal recorded at the land using a laser beam of the optimum intensity determined at the fifth step, and determining the optimum magnetic field intensity according to a magneto-optical signal removed of waveform interference corresponding to the reproduced magneto-optical signal using the optimum equalizer coefficient determined at the sixth step.
A signal is recorded and/or reproduced to/from a magneto-optical recording medium using the phase difference determined at the first step, the optimum pulse beam intensity determined at the fourth step, the optimum laser beam intensity determined at the fifth step, the optimum equalizer coefficient determined at the sixth step, and the optimum magnetic field intensity determined at the seventh step.
In the recording/reproduction method of the present aspect, conditions sensitive to the recording and reproduction properties of signal are determined in priority. The other conditions are determined based on the determined sensitive conditions.
According to the invention of the present aspect, the conditions for signal recording and reproduction can be determined correctly.
According to a further aspect of the present invention, a recording/reproduction method of recording and/or reproducing a signal to/from a magneto-optical recording medium includes a land condition determination step of determining conditions in recording and/or reproducing a signal to/from a land of a magneto-optical recording medium, and a groove condition determination step of determining conditions in recording and/or reproducing a signal to/from a groove of a magneto-optical recording medium.
The land condition determination step includes: a first step of determining an optimum phase difference between a pulse beam and a magnetic field to record a signal onto a magneto-optical recording medium; a second step of recording a signal onto a land of a magneto-optical recording medium using the optimum phase difference determined at the first step, reproducing that recorded signal with a laser beam whose intensity is altered, and determining a provisional optimum laser beam intensity according to the reproduced magneto-optical signal; a third step of recording a signal onto a land of a magneto-optical recording medium using the optimum phase difference determined by the first step, and determining a provisional optimum equalizer coefficient of an equalizer that removes waveform interference of a magneto-optical signal corresponding to the recorded signal reproduced using the provisional optimum laser beam intensity determined at the second step; a fourth step of recording a signal at a land of a magneto-optical recording medium, a first groove adjacent to the land, and a second groove adjacent to the land using the optimum phase difference determined at the first step with the intensity of the pulse beam altered, and determining an optimum pulse beam intensity to record a signal according to a magneto-optical signal corresponding to the signal recorded on the land reproduced using the provisional optimum laser beam intensity determined at the second step, and the provisional optimum equalizer coefficient determined at the third step; a fifth step of recording a signal in the order of a land, a first groove, and a second groove using the pulse beam having the optimum intensity determined at the fourth step and the magnetic field having the optimum phase difference from the pulse beam determined at the first step and the maximum intensity modulated by a recording signal, reproducing the signal recorded at the land with the intensity of the laser beam altered, and determining an optimum laser beam intensity to reproduce a signal according to a magneto-optical signal removed of waveform interference corresponding to the reproduced magneto-optical signal using the provisional optimum equalizer coefficient determined at the third step; a sixth step of recording a signal in the order of a land, a first groove and a second groove using a pulse beam having the optimum intensity determined at the fourth step and a magnetic field having the optimum phase difference from the pulse beam determined at the first step and the maximum intensity modulated by a recording signal, reproducing the recorded signal on the land using the laser beam of the optimum intensity determined at the fifth step, and determining the optimum equalizer coefficient according to a magneto-optical signal removed of waveform interference corresponding to the reproduced magneto-optical signal with the equalizer coefficient altered; and a seventh step of recording a signal in the order of a land, a first groove, and a second groove using a pulse beam having the optimum intensity determined at the fourth step and a magnetic field having the optimum phase difference from the pulse beam determined at the first step and an intensity modulated by a recording signal to be altered, reproducing the signal recorded at the land using a laser beam of the optimum intensity determined at the fifth step, and determining the optimum magnetic field intensity according to a magneto-optical signal removed of waveform interference corresponding to the reproduced magneto-optical signal using the optimum equalizer coefficient determined at the sixth step.
The groove condition determination step includes: an eighth step of of recording a signal to a groove of a magneto-optical recording medium using the optimum phase difference determined at the first step, reproducing that recorded signal with a laser beam whose intensity is altered, and determining a provisional optimum laser beam intensity according to the reproduced magneto-optical signal; a ninth step of recording a signal in the order of a groove, a first land adjacent to the groove, and a second land adjacent to the groove using the optimum phase difference determined at the first step with the intensity of the pulse beam altered, and determining the optimum pulse beam to record a signal first step and the maximum intensity modulated by a recording signal, reproducing the signal recorded at the land with the intensity of the laser beam altered, and determining an optimum laser beam intensity to reproduce a signal according to a magneto-optical signal reproduced corresponding to the signal recorded on the groove using the provisional optimum laser beam intensity determined at the eighth step and the provisional optimum equalizer coefficient determined at the sixth step; and a tenth step of recording a signal in the order of a groove, a first land and a second land using a pulse beam having the optimum intensity determined at the ninth step and a magnetic field having the optimum phase difference from the pulse beam determined at the first step and the maximum intensity modulated by a recording signal, reproducing the recorded signal on the groove with the intensity of the laser beam altered, and determining the optimum laser beam intensity according to a magneto-optical signal removed of waveform interference corresponding to the reproduced magneto-optical signal using the optimum equalizer coefficient determined at the sixth step.
A signal is recorded and/or reproduced to/from a magneto-optical recording medium using the phase difference determined at the first step, the optimum pulse beam intensity determined at the fourth step, the optimum laser beam intensity determined at the fifth step, the optimum equalizer coefficient determined at the sixth step, the optimum magnetic field intensity determined at the seventh step, the optimum pulse beam determined at the ninth step, and the optimum laser beam intensity determined at the tenth step.
In the recording/reproduction method of the present aspect, conditions are optimized independently for the land and groove of a magneto-optical recording medium. A signal is recorded and/or reproduced to/from a land and groove according to the optimized condition.
According to the invention of the present aspect, a signal can be recorded and reproduced correctly.
According to still a further aspect of the present invention, a recording/reproduction method of recording and/or reproducing a signal to/from a magneto-optical recording medium includes a land condition determination step of determining conditions in recording and/or reproducing a signal to/from a land of a magneto-optical recording medium, and a groove condition determination step of determining conditions in recording and/or reproducing a signal to/from a groove of a magneto-optical recording medium.
The land condition determination step includes: a first step of determining an optimum phase difference between a pulse beam and a magnetic field to record a signal onto a magneto-optical recording medium; a second step of recording a signal onto a land of a magneto-optical recording medium using the optimum phase difference determined at the first step, reproducing that recorded signal with a laser beam whose intensity is altered, and determining a provisional optimum laser beam intensity according to the reproduced magneto-optical signal; a third step of recording a signal onto a land of a magneto-optical recording medium using the optimum phase difference determined by the first step, and determining a provisional optimum equalizer coefficient of an equalizer that removes waveform interference of a magneto-optical signal corresponding to the recorded signal reproduced using the provisional optimum laser beam intensity determined at the second step; a fourth step of recording a signal at a land of a magneto-optical recording medium, a first groove adjacent to the land, and a second groove adjacent to the land using the optimum phase difference determined at the first step with the intensity of the pulse beam altered, and determining an optimum pulse beam intensity to record a signal according to a magneto-optical signal corresponding to the signal recorded on the land reproduced using the provisional optimum laser beam intensity determined at the second step, and the provisional optimum equalizer coefficient determined at the third step; a fifth step of recording a signal in the order of a land, a first groove, and a second groove using the pulse beam having the optimum intensity determined at the fourth step and the magnetic field having the optimum phase difference from the pulse beam determined at the first step and the maximum intensity modulated by a recording signal, reproducing the signal recorded at the land with the intensity of the laser beam altered, and determining an optimum laser beam intensity to reproduce a signal according to a magneto-optical signal removed of waveform interference corresponding to the reproduced magneto-optical signal using the provisional optimum equalizer coefficient determined at the third step; a sixth step of recording a signal in the order of a land, a first groove and a second groove using a pulse beam having the optimum intensity determined at the fourth step and a magnetic field having the optimum phase difference from the pulse beam determined at the first step and the maximum intensity modulated by a recording signal, reproducing the recorded signal on the land using the laser beam of the optimum intensity determined at the fifth step, and determining the optimum equalizer coefficient according to a magneto-optical signal removed of waveform interference corresponding to the reproduced magneto-optical signal with the equalizer coefficient altered; and a seventh step of recording a signal in the order of a land, a first groove, and a second groove using a pulse beam having the optimum intensity determined at the fourth step and a magnetic field having the optimum phase difference from the pulse beam determined at the first step and an intensity modulated by a recording signal to be altered, reproducing the signal recorded at the land using a laser beam of the optimum intensity determined at the fifth step, and determining the optimum magnetic field intensity according to a magneto-optical signal removed of waveform interference corresponding to the reproduced magneto-optical signal using the optimum equalizer coefficient determined at the sixth step.
The groove condition determination step includes: an eighth step of of recording a signal to a groove of a magneto-optical recording medium using the optimum phase difference determined at the first step, reproducing that recorded signal with a laser beam whose intensity is altered, and determining a provisional optimum laser beam intensity according to the reproduced magneto-optical signal; a ninth step of sequentially recording a signal on the magneto-optical recording medium in the order of a groove, a first land adjacent to the groove, and a second land adjacent to the groove using the optimum phase difference determined at the first step with the intensity of the pulse beam altered, and determining the optimum pulse beam intensity to record a signal according to a magneto-optical signal reproduced corresponding to the signal recorded at the groove using the provisional optimum laser beam intensity determined at the eighth step and the optimum equalizer coefficient determined at the sixth step; and a tenth step recording a signal in the order of a groove, a first land and a second land using the pulse beam having the optimum intensity determined at the ninth step and the magnetic field having the optimum phase difference from the pulse beam determined at the first step, and the maximum intensity modulated by a recording signal, reproducing the signal recorded at the groove with the intensity of the laser beam altered, and determining the optimum laser beam intensity to reproduce a signal according to a magneto-optical signal removed of waveform interference corresponding to the reproduced magneto-optical signal using the optimum equalizer coefficient determined at the sixth step.
A signal is recorded and/or reproduced to/from a magneto-optical recording medium using the phase difference determined at the first step, the optimum laser beam intensity determined at the fifth step, the optimum equalizer coefficient determined at the sixth step, the optimum magnetic field intensity determined at the seventh step, the average between the optimum pulse beam intensity determined at the fourth step and the optimum pulse beam intensity determined at the ninth step, and the optimum laser beam intensity determined at the tenth step.
According to the recording/reproduction method of the present aspect, conditions are optimized independently for the land and groove of a magneto-optical recording medium. When the optimized conditions differ between the land and groove, a signal is recorded and/or reproduced to/from a land and groove according to conditions corresponding to the average of respective optimum values.
According to the invention of the present aspect, optimum conditions can be determined for the land and groove.